It is known to construct skin care wipes from fabric material comprising laminated nonwoven webs of fibers. In one conventional material the fibers are chemically bonded together using acrylic latex. These wipes are soaked in an aqueous solution containing skin treatment chemicals. This conventional material has the disadvantage that formaldehyde can be produced in the end product. Due to the toxic nature of formaldehyde, this development is highly undesirable.
In a different skin care wipe material known in the prior art, two nonwoven webs are laminated by ultrasonic bonding over an area approximately equal to 25% of the web area. One web comprises 75 wt. % rayon fibers and 25 wt. % polypropylene fibers which are thermally bonded. The other web comprises 70 wt. % rayon fibers and 30 wt. % polyester fibers which are hydroentangled. A logo is embossed on the fabric using a customized anvil roll.
In another known skin care wipe material, two nonwoven webs are laminated by ultrasonic bonding over 12% of the web area. One web comprises a thermally bonded nonwoven web having a fiber composition of 69% rayon fibers, 25% polypropylene fibers and 6% cotton fibers. The other web comprises a hydroentangled nonwoven web having a fiber composition of 50% polyester fibers and 50% polyester/polypropylene (core/sheath) bicomponent fibers. Prior to lamination, the hydroentangled polyester fibers and bicomponent fibers are also bonded during the drying step as a result of radiational heat, causing the surfaces of the polypropylene sheaths of the bicomponent fibers to soften, if not melt, thereby thermally bonding at least some of the bicomponent and polyester fibers together.
This prior art material is disadvantageous in at least several respects. First, the layers having a high content of cellulosic fibers swell appreciably after the fabric is soaked for extended periods of time in an aqueous solution. As a result the visibility of the embossed image in such layers is diminished. Second, the rayon fibers partially insulate the polyester and polypropylene fibers from the heat generated by the ultrasonic vibration. As a result, the ultrasonic bonding is performed relatively inefficiently. Assuming that a constant level of ultrasonic power is available, the required dose of ultrasonic energy is attained by extending the duration of the ultrasonic bonding, resulting in slower production line speeds and increased manufacturing costs. Third, the high content of cellulosic fibers has the consequence that the peel strength of the ultrasonically bonded lamination is relatively low.